This invention relates to a document feeder for use with a photocopying machine having an upwardly facing imaging platen.
In our copending application Ser. No. 624,860, filed Oct. 22, 1975, now U.S. Pat. No. 4,023,791 we have described a document feeder in which original documents are moved across the machine imaging platen by a plurality of parallel spaced belts supported by first and second pulley assemblies, each of the belts having a lower traverse running across the platen. Documents introduced to the feeder through an entrance port located near the top of one of the pulley assemblies are guided around the pulley assembly onto a lower transport path defined by the plurality of belts and the imaging platen and are stopped for copying by a plurality of upwardly extending fingers disposed along the opposite edge of the imaging platen; the fingers are selectively movable between the belts into and out of the path of a document following the transport path. In one of the embodiments shown in our copending application, documents moved past the fingers are guided upwardly and backwardly along a curved path extending somewhat over 180.degree. to a discharge mouth from which documents are discharged into a stacking tray disposed above the belts and the imaging platen.
Our invention relates to an improved stacking means for the above-described document feeder or, more generally, for any document feeder in which documents are fed from below a stacking tray into the tray at one end thereof. We have found that when originals having upwardly turned ends are discharged into the stacking tray, the ends may extend into the delivery path followed by subsequently discharged documents, interfering with delivery and possibly causing crumpling of the documents and jamming. Although increasing the height of the discharge port or mouth relative to the bottom wall of the stacking tray might be thought to solve this particular problem, such an expedient not only increases the bulk of the feeder but also increases the chances that the loading edge of the document will curl under during delivery. Moreover, as a matter of fact it does not solve the problem of possible interference with a document already in the bin or tray.